SA111320424B1 - Titanium Dioxide Pigment Particles with Doped,Dense SiO2 Skin and Methods for Manufacture - Google Patents

Abstract

The invention relates to titanium dioxide pigment particles which have improved photo stability, their surface being coated with a dense SiO2 skin that is doped with at least one doping element. The SiO2 skin is characterized in that the doping with the at least one doping element reduces the energy level densities in the valence band and/or in the conduction band in the vicinity of the band gap or that additional energy levels in the band gap are produced. The doped dense SiO2 skin is applied using known wet-chemical methods or is applied in the gas phase to the surface of the titanium dioxide particles. Particularly suitable doping elements are Sn, Sb, In, Ge, Y, Nb, F, Mn, Cu, Mo, Cd, Ce, W and Bi. The following known doping elements AI, B, Ge, Mg, Nb, P, Zr for the gas phase method and Ag, AI, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Mg, Mn, Ni, Nb, Sn, Sr, Ti, Zn, Zr for the wet-chemical method are excluded from the invention.

Description

—y- Titanium Dioxide Pigment Particles Covered with Silicon Dioxide-Like Dense Layer 8:02 and Methods of Manufacturing Them

Titanium dioxide pigment particles with doped,dense SiO; skin and methods for manufacture Full description Background of the invention This application is a partial application of Application No. 17080017, which was filed in the Kingdom ca Yev 1 / YA 1 H corresponding to 1/4/470 Saudi Arabia on dated Which provides titanium dioxide J pigment particles The present invention relates to pigment particles whose surface has a thick 5:0 layer containing doping elements; and methods of manufacturing. © . Greater photostability for light. Leslie titanium dioxide pigment for it is used » titanium dioxide for high refractive index due to the high refractive index of plastic Jie sectors in many sectors high-quality pigment As a high-quality pigment, though; fibres, fibers, paper, coatings and coatings ¢ plastics; That is, photocatalytic reactions such as titanium 0 occur as a result of unwanted photocatalytic reactions: ; This leads to UV absorption

The Chemical Nature of Chalking in the Presence of Titanium Dioxide Pigments, H. G.

Volz, G. Kaempf, H. G. Fitzky, A. Klaeren, ACS Symp. Ser. 1981, 151,

PhofRlegradation and Photostabilization of Coatings

in this context; titanium dioxide absorbs light in the UVB range; Which results in pairs of electron-hole ¢ leading to the formation of highly reactive radicals on the surface of titanium dioxide surface a stil). The cracks produced in this way result in the dissolution of the adhesive in an organic media © . It is proven through practical studies that hydroxyl ions play a major role in the photocatalytic process Photocatalytic Degradation of Organic Water Contaminants: Mechanism Involving Hydroxyl Radical Attack , C.

S.

Turchi, D.

F.

Ollis, Journal of Catalysis 122, 1990, 178- 192 0. It is known that photoactivity of TiO can be reduced by dyeing TiO particles; titanium =) for example or by dallas method. Meanings of inorganic surface treatment (eg by coating with oxides of silicon, aluminum, and/or zirconium). Industrial Inorganic Pigments, ed. by 6. Buxbaum, VCH, New York 1993, Seite 58 - 0.60 ald. Several patents have shown the placement of a denser amorphous 8:02 layer on the particle surface; this is known as the "dense layer". dense skin". The purpose of this layer is to prevent the formation of free radicals on the surface of the particles. Wet-chemical methods have been shown to produce a dense film of :8:0; as well as an ALO;70 coating. 0

It is available in organic particles »in particular (TiO) in patent numbers 1408717 and 4178417 and 17/8148 USRE European patent No. 17,206414 BI refers to a method that can be carried out at relatively low temperatures. range from 15 to 900°C; as a result of the immediate addition of a solution of NaySiOs and a solution of B03©, dense-skin treatments of 8:02 are also performed to increase the abrasion resistance of the glass fibers Coated in this way and reduce the sliding properties of the fibers in the products that are manufactured.In this regard, US application No. 7917419 shows a wet-chemical method Led to deposit silicic acid on the particle surface. With polyvalent metal ions “Cu Jia ¢ polyvalent metal ions” Rev “Sry” Cas “Bes Mgs 0 Ribs Nis “Cos Mn “Crs” Pb “Sn Zr “Tis “Als” Cds according to German Patent No. 017000-646797791 1 ) ; The method increases the light resistance of dense layer pigments 10. It is based on Merge 80; or 21 or Zr in a layer of 8:0 used by the wet-chemical process. In addition to the well-known wet chemical methods for surface coating of TiO particles, there are also VO methods through which a thick layer of 0:8 is deposited in the gas phase. In this case; during the production of titanium dioxide by By the chloride process ¢ a silicon compound ¢ preferably 4 is added to the particle stream at a temperature higher than 10001 degree so that a dense and uniform layer of 5:7 is formed on the particle surface. European No. 0147404 gas phase method for surface coating with: oxide 0 81 and 5 or P or Mg or Ge Nb.

And

This is solved by using pigment particles of titanium dioxide which

Its surface is coated with a dense layer of SiO, which is deposited in the gas phase and impregnated with

with at least one doping element; Where the similarity element is determined from

The collection that includes “Ins” “Shs” “Sn” “Balak Ra’la Asla” Ratl Mny “Yift Rimal” “Ces” CDs

©, 17, and 31, as well as mixtures thereof.

The matter is also solved by using pigment particles of titanium dioxide which

Its surface is coated with a thick layer of 58:0 produced in a wet-chemical (duh) process

and doping it with at least one doping element; from which aie is specified

The homologue is from the group comprising “Ys<Gey ny”Sb and lac “Ce”Mo ¢F 177 and Bi as well as 0 mixtures thereof.

The material is also dissolved using a method for manufacturing pigment particles for titanium doping, whose surface is coated with a thick layer of 0:5 doped with a dioxide-like element.

element on JY and it includes the steps:

1 Reaction of titanium tetrachloride in the gas phase with aluminum halide and the oxygen-containing gas Yo in a reactor at a temperature above 1011 °C; in order to create

A particle stream containing TiO particles

b) Contacting the particle stream with two compounds on (JN), where

The first compound is a silicon oxide-producing compound, and the second compound is determined from the included group

_ 1 Ab on “Y 5” Ins “Sb” Sn Ra’a “Wg” Ces “Cds < Mos” Cus Mn “Zn and Bi and the compounds produced for 7 as well as mixtures thereof. c) cooling of the particle stream; In order to create pigment particles that are coated with a thick layer of SiO, they are doped with at least one doping element © of the Shy “Sn-containing group” and ZnsZrs and

It is said W 5 ¢ “Ces “Cds Mos” Cus and 31 as well as mixtures thereof. yal There is a solution AT for this matter, which is a method for manufacturing pigment particles for titanium dioxide, the surface of which is coated with a thick layer of 8:07 doped with at least one doping element »and it includes the steps :

pH (Lead pH) that increases the value of TiO, for aqueous solution particles (Ale) by providing a solution of 1 001 00 for an alkaline silicon solution of an aqueous solution by adding an aqueous solution « doping element at least one of a component containing an aqueous solution “Fg” Nb 5 and no “Ge g “Ing 4 Sb Ae” of an aqueous solution of the group J, where an element is specified

VO, m, 6177©, and 3: as well as mixtures thereof. c) Deposition of a dense film of 5:02 doped with at least one doping element on the particle surface by reducing the pH value of the suspension to a value less than 9; It is preferable to be less than oA, since the dopants are selected from the group comprising “Mo Fy “Nb” Ys “Ge Ing ¢ Sb, Ce Ww and Bi, as well as mixtures thereof.

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Other distinct embodiments of the invention are indicated in the subsidiary claims. The material of the invention is coated with titanium dioxide pigments which are improved in terms of their light resistance. General description of the invention o© according to the present invention; The pigments present in the form of a dense layer on the surface of a fitanium dioxide particle contain “0 goats, ranging from 0.1 to 71.0 by weight; preferably from 1.7 to 5.0 by weight; And he is counted as a distributor; ala elements range from 000 to n wt ¢ and preferably from 0.69 to 1 wt; It is calculated as oxide or in Alla using 7 as the dad element to the total pigment . 0 in preferred form; Particles are coated with an additional layer of 4.0 to 1.0 wt.; preferably from 0.1 to 4.0 by weight” aluminum oxides hydrous aluminum oxide; It is calculated as ALO; relative to total hemoglobin. It is preferable that the titanium dioxide particles be of the rutile type. Here, "doping element" means the special element such as atom or 108 or a special compound VO such as oxide; Where appropriate. In the context of a statement on coatings that are produced using a wet-chemical process; Here, the word “oxide” also means analogous oxide compounds or analogous hydrates. It must be stated that all the data disclosed here regarding the pH value; temperature; concentration by 7 by weight or 7 by volume; etc. Include all values within their respective measurement accuracy range known to a Yeo handyman

m - sphere. The invention is based on the fact that to increase the resistance to light; The photocatalytic process 5 must be appropriately demonstrated; That is, it must be made more difficult to produce highly effective cracks using excited electron-hole pairs. This can be achieved using several mechanisms; © For example by increasing the speed of re-fusion of electron-hole pairs or by creating an active barrier on the surface of the pigment. A dense layer of 58:02 applied in a system does indeed form an active barrier on the TiO surface; this can be revealed by the energy diluted Ala density in the valence band and in the transmission band of the TiO surface. , coated Compared to TIO surface, untreated. Surprisingly, doping the 0:5 layer with specific elements leads to a greater reduction in the ABN state and this raises the active barrier and thus improves the photoresistance of the TiO pigment, coated in this way. Additional states of energy within the band gap between the valence band and the transport band promote the recombination of the electron-hole pairs. The doping of the SiO2 layer with bound elements induces these energy states and thus also influences the improvement of the photoresistance Lie of the non-doping element SiO2 layer. It has been proven that the metals “Sn Ray Eml” Ys “Gey Wei Mog Cus Mn Fs Zn Nb Ces Cds and 7; and Bi are suitable analog components. A layer of 0.58:0 containing dopant elements can be applied by the wet-chemical method and the gas phase method. Nevertheless; It is known that the gas phase method is generally able to lay a more uniform layer than the wet chemical method. Yeo

An example of the present invention is described below using Figures 1 through AA Brief explanation of the drawings FIGURE 1 : Shows the energy states of the phase transition from atom to solid | solid (shown in: P.A.

Cox, "The Electronic Structure and Chemistry of Solids", Oxford Science 5 Publications 1987, p. 13 figure? 0 a TIO2 energy state density surface with or without 8:02 coating. the shape ? : shows the energy state density of a TiO surface, with a SiO coating; and with a SiO coating, containing any Sn dopant element 0 Fig. ; : shows the energy state density of a TiO surface, with a SiO coating; and with a SiO coating, containing the figure © : shows the energy state density of a TiO surface, with a SiO coating; and with a SiO coating, containing an ale For In analogue Figure 1: Shows the energy state density of the TiO surface, with SiO coating, and with SiO coating, containing Yo-doping element Ge. Figure 7: Between the energy state density of the In alloy surface TiO, with SiO coating; with SiO coating, containing 0.5% dopant

- 11 with coating 5107 and coating 510 containing TiO, showing the energy state density of the surface of: Figure A containing SiO; with SiO coating; With TIO coating, Figure 4: Between the energy state density of a surface

JF SiO-containing doppelgänger; And with a coating of Si0, with a coating of TiO, the energy state of a surface da shows the density: 0. Figure 5: element J for Mn analogue. Figure 11: shows the energy state density of a surface of TiO, with a coating SiO, with Si0 coating, containing .Cu dopant. Figure VY shows the Alls surface energy density of TiO, with Si0 coating, and 8:0 containing coating

Mo is a Yo-like element containing SiO; with SiO coating; With TiO coating, showing the energy state density of a surface : Fig. 11 Cd SiO-containing doppelgänger, with SiO coating, with TiO coating, showing the energy state density of a surface : Fig. VE ,. Ce doppelgänger Ve Figure Vo: shows the energy state density of a TiO surface; with a SiO coating; and with a coating: 8:0 containing Shic 01: shows the energy state density of a TiO surface, with a coating SiO, with a SiO coating, containing .Bi dopant

Figure VY: shows the energy state density of a TiO surface, with a SiO coating; and a SiO coating, containing Mg dopant. Figure YA shows the energy state density of a TiO surface, with a 510 coating and a SiO coating , containing © Alla energy density values were quantitatively calculated using the CASTEP software package (version 1 1 June 0011) from San Diego. These calculations were performed using the CASTEP density functional code in the local density approximation (detailed information published by: 910 895 A.M. (2000) 77 V.

Milman et al. in; International Journal of Quant.

Chemistry Vo The following valence states were used; including subterranean 4s 53d 3p. "3s stitanium 4p valence states 2s and 2p were used for oxygen; And the valence states 3p 53s of silicon for doping elements, then include the subterranean aud cases 4d or 45 and 4p or indium A 2p ¢ magnesium 5 yttrium 5 . Here is the base group used for the dopants: 5s, Sp, 6s, 6p, 5 Sn: 5s, 5p, 6s,6p, 7s Sb: Yo 4d, 5s, 5p, 6s, 6p, 7s In: 4s, 4p, 4d Ge: 4s, 4p, 4d, Ss, Sp Y:

Nb: 4s, 4p, 4d, 5s, Sp

F: 2s,2p

Mn: 3d, 4s, 4p

Cu: 3d, 4s, 4p

Mo: 4s, 4p, 4d, 5s, 5p©

Cd: 4d, 5s, 5p, 6s, 6p

Ce: 45 5s, 5p, 6s, 6p, 7s, Tp, 8s

W: 5d, 6s, 6p

Bi: 6s, 6p, 7s, 7p, 8s 2p, 3s,3p Mg: Ye 3s, 3p Al: electron volts. Geometric optimization YA was not achieved. The cut-off kinetic energy of the plane waves according to the experimental results was 85 Ly. As it was possible to evaluate the mathematical model and ensure that it is sufficient to calculate ia and thus; Availability of model accounts. (Zn, Zr, and Sn - known (photoresist coatings). 1 State density calculations are based on a grid according to the Monkhorst-Pack scheme. Surface calculations were performed according to the “slice model method” with a blank thickness of 01. Angstrom.

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Y —_ \ — Examples The invention is demonstrated based on Examples 1 to VE (doping the SIO layer; with an element of the “Sb” Sn doppelgänger Nb ¢Y”Gey bond and Rala Bis (Ws “Ces” Cdy Moy “Cus) and comparator example 1 (pure layer of SiO), comparator y (homologous to SiO; b (Mg) and comparator example © (Collection 8: 0 b (Al) Calculation of reference example 1 is based on covering the surface of TiO;(111) in the entire 8:02 monolayer. In this context, the unit cell contains an OY atom (118518036). When coverage is applied Monomolecular calculated with 5:0 ded has a layer of approximately 1.7 nm on the pigment; it results in approximately a ZY-by-weight ratio of 8:0; relative to TiO; 0 percent calculated by weight based on the following values: Typical specific surface value (relative to 7) for THO particles; manufactured using the chloride process: 1.7 m"/g; monolayer delamination: LY nano meter; layer density (810: 1.7 body). Models from 1 to VE and comparison examples ¥ and 3 show TIO surface coverage, with a monomolecular 0:8 layer containing a doping element at an atomic ratio ranges from 1 (domain element Vo: (X VO (n8); Meaning that the unit cell contains 1188:7721036. When applied to the pigment (TiO; this results in the following ratios by weight of the alloy elements; calculated as oxide and attributed to 1102: Ex 0.01 : 1 approx 7 by weight of S05 Ex 2 approx 70.04 by weight From Sby03 example “: 0.04 7 wt. 0 approx]; mm

And 1 Exodus 4:17. 7 wt. of “GeO, eg. 20 lbs.) + approx. wt. of 505 Example 7: approx. 0.09 wt. of NbyOs. Example 7: approx. 0.00 wt. of l©. Example 8: 0.1 by weight of MnO, ex 9: 70.056 by weight of CuO approx 0.1 : 70.00 by weight of MoO; ex: 11 7.04 by weight from 040; ex y VY 0 + approx wt y 0 e; ye approx 17: 2,11 wt WO; ex VE 70.04 approx wt 3120 reference 7: 0,07 7 wt. of MgO Reference Example 3: 4 0.0 7 wt. Spatially resolved energy energy bands

Vo — - spatially resolved or integrated energy states. Figure 1 shows a simplified schematic diagram (d) of the electronic structure. The schematic diagram shows the energy bandwidth The state density (©) is used to distribute the energy state in the © energy band. TIO, for light: The calculated state density of the pure (111) THO surface is shown as a broken line; and for the SiO-coated surface as a solid line. The positive effect of the 8i0 coating is based on the photostability. partly Wits reduces the 0-state density in the (08) transmission band compared to the uncoated TiO surface, resulting in less transmission of electron-hole pairs into the adjacent matrix.At the same time, the effect is intensified to positive due to the additional decrease in AES the case in the value band Figure 7 shows the effect of doping the 8:0 layer with Sn (Example 1) on the state intensity values compared to the S10 coating; . In this case; The intensity of the valence band state will decrease further; Which results in providing 0 greater resistance to light. improved photostability showing shapes from ; to + the effect of 5:02 layer analogy with 85 (example oY Fig. 4;); In (example oY Fig. ©) Ge (example Jal 1) and 7 (example co Fig. v) and tla (example 1 Fig. L(A) it is surprising that it can The appearance of the decrease in the valence band state intensity in each case; ie

These coatings lead to increased paint resistance. Doping the 5:0 layer with element #2 or 20 also results in greater stability compared to the uncoated Adda 8:0. Figures 9-11 show the effect of analogizing the 8:02 layer with F (example oY Fig. 1); and Mn© (Example eA Fig. 10); Cu (ed Jul) Fig. Mos) 11 (Example 10; Fig. 11); and Cd

(Example ony Fig. Ce 1 VY (Example 0; Fig. ye 1 and A (Example 0- yo Jal) and Bi (Example 0; Fig. 11). It is amazing. The analogy of a layer of 8:0b!”, Mn, Cu, M40, 0©, ce 177, or Bi to additional energy states in the band gap that act as centers for fusion pairs. electron-hole and thus to a greater resistance to light.

Figure 117 shows the effect of doping the SiO layer with Mg (comparison example (Y) on the Alla energy density values. In this case, the valence band state density will increase, meaning that Doping the 810 layer with Mg will lead to non-photoresistance Figure YA shows the effect of doping the SiO layer with AL (comparative example?) on the energy state density values. In this case, the Ala density will increase The equivalence range » that is, the similarity of the 58:02 layer with Al will lead to no

0 Photoresistance. Process control Methods for coating titanium dioxide particles with a thick layer of 510 were shown. working | for conventional processes through the aqueous phase. To this end; A particulate suspension is produced

0.0

17 - - “TiO, and mix it with a dispersant material wherever that is Lilie and grind it wet where appropriate. Gale is precipitating a thick layer of 5102 by adding alkali metal- silicate solutions and an appropriate control element at the pH value of 11m. The doping element is added in the form of brine combined with silicate solutions © or separately before or after adding the silicate solution Skilled in the art knows the appropriate compounds

And the quantities needed to control the pH value to produce a dense layer. According to this invention; The imitation of a thick layer of 8:02 can be done by adding the following salts to the suspension; Provided that it is not understood from this combination that the invention is limited to it. Similarity to: Sb

antimony chloride, antimony chloride oxide, antimony fluoride, antimony sulphate AK indium chloride, indium sulphateIn: Ge: germanium chloride, germanates: Ge: yttrium chloride, yttrium fluoride: Y: niobium chloride, niobates: Y Similarity: Nb b

Florine hydrogen, fluorides: F Component B: manganese chloride, manganese sulphate: Mn Component: copper chloride, copper sulphate: Cu Component: molybdenum chloride, molybdates: Mo Component: cadmium chloride, cadmium sulphate: Cd analogy b

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z - YA - cerium nitrate, cerium sulphate: C, wolframates: W, bismuth nitrate, bismuth sulphate: Bi in a particularly favored embodiment; Traditionally, an outer layer of aqueous aluminum oxide© is applied to the particles by the usual methods. In another embodiment of the invention; A dense layer of Si0; is deposited on the surface of the gas phase. There are many known methods for this. For example; Fluidized bed coating is possible at temperatures below approximately 1,000°C. These methods are described in US Patent No. Yoovado or UK Patent No. 1 07 or US Patent No. E A A Yau, of that; The coating takes place in a tubular reactor immediately following the formation of TIO particles;the chloride process ¢ These methods are described; For example »in patents or patent applications International Application No. 48/077441 - 1; EP No. 7197784” 1B, EP No. 74507 1010-01b, EP 081411/11 - ?a. for plating in a tubular reactor; 0 The compound produced for 8102 is usually silicon halide; In particular (SiCly) which is generally introduced after the point at which the reactants TCL and AIC are combined with the oxygen-containing gas. For example (JU) International Application IY - 01/081411 indicates that Silicon vie halide is added (the point at which the TIO formation reaction is complete) with a ratio of at least 7299. In any Als the temperatures at the entry point must be greater than 10001°C; 0701 degrees Yo is preferred. The producing compound of 8102 is oxidized and deposited on the surface of the TIO particles, in the form of a dense film.

from silicon dioxide. In contrast to the ewet-chemical method, free oxide layers of water and hydrates are formed during gas-phase treatment, leading to the absorption of hydroxyl ions and water molecules. Jad molecules on the surface. © A particle stream is also added as a product compound; Either parallel to, before, or after the compound product of 2. The temperature of the particle stream at the point of entry must be greater than Agia ia 011 preferably YY vo degree. The following compounds in a product compound suitable for metal oxides compounds » provided that this combination is not understood to be exclusive to this invention. Similarity to as tin chloride Jie ¢ tin halide: Sn 0 Similarity to antimony halide: Sb ¢ Like antimony chloride Similarity to indium chloride Jie ¢ indium halide: In Similarity to: yttrium chloride Jie ¢ yttrium halide Similar to zirconium halide: Zr ¢ Like zirconium chloride Similar to zinc chloride Jie ¢ zinc halide: Zn 0 Similar to niobium chloride Jie ¢ niobium halide: Nb Similar to fluorine, fluorine hydrogen, fluorides: F, resemblance to manganese chloride: Mn

Nor the analogy with copper chloride:Cu the analogy with molybdenum chloride:Mo the analogy with cadmium chloride:Cd the analogy with cerium chloride:Ce© the analogy with tungsten chloride:W the analogy with bismuth chloride:Bi in a particularly favored form; Traditionally, an outer layer of aluminum oxide is applied to the particles by the methods known by the introduction of a suitable product compound for aluminum oxide; Jie “AlCl; is a particle post-stream.

01 Finally, titanium dioxide pigments that are provided with a layer containing densely linked elements of 8:02 can also be processed by methods Ag peal regardless of Lee if they have been coated in suspension or in phase gaseous gas phase . For example; It is also possible to put inorganic layers of one or more metal oxides on it. Further surface treatment can be done with nitrate and/or organic surface treatment

Organic surface treatment Vo compounds known to a skilled artisan for the organic surface treatment of pigment particles of titanium dioxide are also suitable for the organic surface treatment of the Wy particle surface of the present invention; for example JE) organosilane 265+, organosiloxanes ¢, organophosphonates “etc; or polyalcohols;

trimethylethane (TME) Jie or “trimethylpropane (TMP) etc. According to the present invention; The pigment particles of titanium dioxide are suitable for use in paints; And paint and paper. It can also be used as an indentation

production hold For example; Paper or coatings.

Claims (1)

yy - — Protection elements titanium dioxide(110) pigment particles 1-1 pigment particles include: 7 0 core particles of titanium dioxide ( TiO) ¢ ; . (b) a dense crust of (0:5) dense silicon dioxide covering the core particles©; Dense skin is produced in a wet-chemical process 1 Dense skin is doped with at least one doping element 0 where V is selected for one doping element at least of the group consisting of F (Nb “Y” Ge) Mo A 77 and 31 ml and mixtures thereof. titanium dioxide (110) L pigment particles — Y 1 according to of protection 1, which also includes: Y z ¥ additional coating of aluminum oxide hydrous aluminum oxide 1 when covering the dense layer.dense skin titanium dioxide (TiO;) SU of pigment particles Y 1 —6.0 to 0.9 for additional coatings in aluminum where the oF content varies depending on the protectant. ALO; is by weight and is calculated as LY 9.6 titanium dioxide (LS-110) of pigment particles; Where the content of Gy, 1 ranges by weight. titanium dioxide (TiO) pigment particles from 1 —0 + to dense skin silicon Cus content ranges from 1 According to claiming dense silicon dioxide (Si0) by weight and calculated as silicon dioxide 72 4,0 Y . total pigment is referred to as € titanium dioxide (TiOy) pigment particles 1-1 to 0,” from dense skin silicon ranges Cua© content according to the claim ¥ dense silicon dioxide by weight; calculated as silicon dioxide (and 0:8) 0 ¥ total pigment and denoted as total pigment ¢ titanium dioxide (TiOz) Titanium pigment particles -1/1 of 06058 skin where the dopant content in the protective layer 1 Gy Y calculated as F Ala and in oxide ranges from 0.0 2 to 0.0 2 By weight; it is calculated as 0.00" element. ¢ titanium dioxide (TiO2) pigment particles =A) of dense skin | For alloy in the thick layer Cua ¢ of protector No GE, Y to A 7 wt. 1,00 y vs - 1 4- A method for manufacturing pigment particles from titanium dioxide JAdioxide (1102) ¥ coating its surface with a dense layer of silicon dioxide (59502) It is doped using a single doping element on “JN” and includes; the steps: 8 0) provide an aqueous suspension of Cus (TiO2 core particles) 1 aqueous suspension having a pH greater than 10; For (b) the addition of a solution (Sle) of an alkali silicon component and at least one aqueous solution of a component containing at least one doping element, whereby at least 4 of the doping element is selected of the group consisting of Y “Ge dn (Nb 0 for W Mo and Bi and mixtures thereof; 1 (c) lowering the pH value of the suspension to a value less than 1 to produce a dense crust of dense silicon dioxide (Si02) doped with at least one doping element deposited on core particles 1102. -1 01 of the method in accordance with claim 9; where Und comprises: ¥ (3) adding an aqueous solution of an aluminum-containing component to the suspension to produce an additional layer of aluminum oxide Y or hydrous aluminum oxide on a second shell; Dense silicon dioxide (Si02). Yio _ Y o — -11 1 Method of claim 10; wherein Wad comprises: ¥ (e) addition of an aqueous solution of an organic component to produce an additional layer of organic matter on an aluminum oxide ~~ v layer or Hydrous aluminum oxide. VY) the Gay method of claim 101 where it also includes: ¥ (f) the addition of pigment particles 1102 produced in step (e) to a process for the manufacture of plastics or paints paints » or coatings » or paper. -1-1 method in accordance with claim 10; Cua Wad comprises: (e) the addition of pigment particles 1102 produced in step (d) to a ¥ process for the manufacture of plastics; paints ¢ or coatings » or paper. dense for claimant 9; Where the silicon content in the dense layer ranges from Ga, method 6 - 1 dense silicon by weight; It is calculated as silicon dioxide Lhe to 0.1 askin Y . total pigment Jab denoted as dioxide (Si02) |" dense Silicon content in the (Cum) layer of the protector ag Method - 1 dense silicon by weight; calculated as silicon dioxide Lge to 0.7 means from 1. total pigment and is referred to as total pigment dioxide (Si02) 6.5 10 -11-1 Method in accordance with claim 4; The content of dopant elements in the density skin Y ranges from 0.0 to 0.1 / wt and is calculated in oxide form or in Ala 1 in element form. -17 1 The Gig method for the protection element O71, where the content of similar elements in the dense skin layer Y ranges from vive to Ye 7 by weight and is calculated in the form of oxide in the case of SF V is the image of an object. VA) Method Gy of claim 4 where Wall includes: Y (d) Addition of pigment particles of (1102) titanium dioxide produced in ¥ step (z) to a process for the manufacture of plastics + or paints ¢ or coatings ¢ Or paper —V 4 1 pigment particles of ctitanium dioxide (TiO2) including: (T) core particles of (1102) ‘titanium dioxide’ YF (b) Dense silicon dioxide ($102) covers the core; the dense skin; produced in a wet chemical process; the dense layer is doped with one doping element On Cus (JW) at least one dopant element either reduces the density of states near the band edge or creates (Alia) states in the band gap of the dense layer material; VY except for the alloy elements that are selected from the group consisting of (Ag) for Be Ba B “Mg” Cu “Cr” Ce “Co” Cd “Ca A per “Zn” Ti “Sr Sb Sn Pb and Zr Yio